The current paper is focused on analyzing the flow of viscoplastic fluid in a cavity that is driven by the two walls. The Lattice Boltzmann method (LBM) is used to solve the discrete Boltzmann equation. To represent the stress-strain rate relationship of viscoplastic fluids, the Bingham Papanastasiou constitutive model is considered. Cavity flow filled with Bingham fluids is considered for

Here, analytical solutions are developed for the constant‐speed squeezing flow of viscoplastic fluids. It is assumed that the fluid is purely viscous, and hence viscoelastic effects unimportant. The rheological behavior of the viscoplastic fluids is represented by the Herschel‐Bulkley viscosity function.

First Online 27 October 2016; DOI https://doi.org/10.1007/978-3-319-44362-1_3; Publisher Name Springer, Cham; Print ISBN 978-3-319-44361-4; Online ISBN 978-3-319-44362-1; eBook Packages Mathematics and Statistics; Buy this book on publisher's site Afonso Paiva, Fabiano Petronetto, Thomas Lewiner, Geovan TavaresSimulations of viscoplastic materials are traditionally governed by continuum mechanics. The 40.10 Viscoelastic Fluids. These are fluids that have the ability to store and recover shear energy and, hence, show some properties of a solid and some properties of a liquid. There are two easily observable examples of viscoelastic behavior: The rheological behavior of the viscoplastic fluids is represented by the Herschel‐Bulkley viscosity function. The deformation behavior of commonly encountered viscoplastic fluids is generally complicated by the presence of wall slip at solid walls, which is a function of the wall shear stress. The archetypal feature of a viscoplastic fluid is its yield stress: If the material is not sufficiently stressed, it behaves like a solid, but once the yield stress is exceeded, the material flows like a fluid.

Viscoplastic fluids

2011. Albert Magnin. Download PDF. Download Full PDF Package. This paper.

A Bingham material remains rigid when the shear-stress is below the yield stress τ 0 , (here, equivalent to the Bingham number, Bn, as in Mitsoulis 2007), but flows like a Newtonian fluid when the shear-stress exceeds τ 0 .

Heat transfer prediction of in-service welding in a forced flow of fluid An Eulerian thermomechanical elastic–viscoplastic model with isotropic and directional

Rate-dependence in this context means that the deformation of the material depends on the rate at which loads are applied. The inelastic behavior that is the subject of viscoplasticity is plastic deformation which means that the material undergoes unrecoverable deformations when a load level is reached. Rate-dependent plasticity is important for transient plasticity Viscoplastic fluids in forming processes D. Ian Wilson Department of Chemical Engineering and Biotechnology New Museums Site, Pembroke Street, Cambridge, CB2 3RA, UK Abstract Many industrial applications of viscoplastic fluids are to be found in forming processes, 2019-11-23 · When viscoplastic fluids are agitated by a central impeller within a vessel, a ‘cavern’ can form.

viscoplastic constitutive model. The parameter of the over a cylindrical fluid element in fully developed, steady state, laminar flow in a pipe. The limitation of the

foams, pastes, slurries, oils, ceramics, etc.) exhibit the fundamental character of viscoplasticity, that is the capability of flowing only if the stress is above some critical value. The key feature of a viscoplastic fluid is its yield stress: material only flows like a fluid if the stresses exceed a critical yield threshold. The consequence for a cylinder moving through a viscoplastic fluid is that there is no motion if the force on the object is insufficient to yield the fluid. G. Ovarlez, S. Cohen-Addad, K. Krishan, J. Goyon, P. Coussot. Pages 68-79. Download PDF. Article preview.

It is composed by two differential equations, one for the stress and the other for the structure parameter—a scalar quantity that represents the structuring level of the fluid. Rayleigh-Bénard convection for viscoplastic fluids @article{Darbouli2011RayleighBnardCF, title={Rayleigh-B{\'e}nard convection for viscoplastic fluids}, author={Mohamed Darbouli and Christel M{\'e}tivier and J. Piau and A. Magnin and Ahmed Abdelali}, journal={Physics of Fluids}, year={2011}, volume={25}, pages={023101} } An important class of non-Newtonian fluids presents a yield stress limit which must be exceeded before significant deformation can occur – the so-called viscoplastic fluids or Bingham plastics. In order to model the stress-strain relation in these fluids, some fitting have been proposed such as the linear Bingham equation and the non-linear Herschel-Bulkley and Casson models. Viscoplastic materials behave as solids subject to a small applied force, but flow like a fluid when the applied force is large enough.
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The 40.10 Viscoelastic Fluids. These are fluids that have the ability to store and recover shear energy and, hence, show some properties of a solid and some properties of a liquid. There are two easily observable examples of viscoelastic behavior: The rheological behavior of the viscoplastic fluids is represented by the Herschel‐Bulkley viscosity function. The deformation behavior of commonly encountered viscoplastic fluids is generally complicated by the presence of wall slip at solid walls, which is a function of the wall shear stress.

Applications. Two-part epoxy adhesive with good stability under static and dynamic loads (vibration and impact). Viscoplastic.
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Numerical flow simulation of viscoplastic fluids in annuli. The Canadian Journal of Chemical Engineering 1998, 76 (1) , 27-40. DOI: 10.1002/cjce.5450760105. YEH WANG. AXIAL FLOW OF GENERALIZED VISCOPLASTIC FLUIDS IN NON-CIRCULAR DUCTS. Chemical Engineering Communications 1998, 168 (1) , 13-43

Below this critical stress, the material behaves like an elastic solid. If the applied stress exceeds the yield stress, the material flows like a viscous fluid, typically featuring a nonlinear shear-dependent viscosity. The archetypal feature of a viscoplastic fluid is its yield stress: If the material is not sufficiently stressed, it behaves like a solid, but once the yield stress is exceeded, the material flows like a fluid. Such behavior characterizes materials common in industries such as petroleum and chemical processing, cosmetics, and food processing and in geophysical fluid dynamics.